Temporal variation of the activity of intermediate and deep focus earthquakes

Abe, Katsuyuki; Kanamori, Hiroo

doi:10.1029/jb084ib07p03589

Cited by 76 publications

(25 citation statements)

References 21 publications

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“…00:22:13, 25 1/2°N, 122 1/2°E, H = 200 km, M = 7¾). Abe & Kanamori (1979) list m B = 7.6 for the 1910 earthquake which was computed from the Gutenberg Notepad. We found a good Wiechert seismogram (EW) for this event recorded at Göttingen (Fig.…”

Section: Tectonic Interpretationmentioning

confidence: 99%

The 1909 Taipei earthquake-implication for seismic hazard in Taipei

Kanamori¹,

Lee

Fong

2012

Geophysical Journal International

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SUMMARY The 1909 April 14 Taiwan earthquake caused significant damage in Taipei. Most of the information on this earthquake available until now is from the written reports on its macro‐seismic effects and from seismic station bulletins. In view of the importance of this event for assessing the shaking hazard in the present‐day Taipei, we collected historical seismograms and station bulletins of this event and investigated them in conjunction with other seismological data. We compared the observed seismograms with those from recent earthquakes in similar tectonic environments to characterize the 1909 earthquake. Despite the inevitably large uncertainties associated with old data, we conclude that the 1909 Taipei earthquake is a relatively deep (50–100 km) intraplate earthquake that occurred within the subducting Philippine Sea Plate beneath Taipei with an estimated MW of 7 ± 0.3. Some intraplate events elsewhere in the world are enriched in high‐frequency energy and the resulting ground motions can be very strong. Thus, despite its relatively large depth and a moderately large magnitude, it would be prudent to review the safety of the existing structures in Taipei against large intraplate earthquakes like the 1909 Taipei earthquake.

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Section: Tectonic Interpretationmentioning

confidence: 99%

The 1909 Taipei earthquake-implication for seismic hazard in Taipei

Kanamori¹,

Lee

Fong

2012

Geophysical Journal International

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“…A number of potentially shallow thrust earthquakes with magnitudes greater than 7.0 occurred from 1900 to 1950. Many of these events, listed by Gutenberg and Richter [1954] as shallow or intermediate depth earthquakes, have revised magnitudes between Ms 7.0–7.4 [ Abe and Kanamori , 1979; Abe , 1981; Pacheco and Sykes , 1992] and occur along the entire length of the Mariana forearc (Figure 2 and Table 1, events 6–13). Although some of these events are classified as intermediate depth earthquakes, and a few are located in the outer rise of the Pacific slab, they are included in the record due to the possibility of poor event locations in the early 1900s – up to 1° laterally and 30 km in depth for the best‐located events, with earthquakes at 40–100 km depth being particularly problematic [ Gutenberg and Richter , 1954].…”

Section: Introductionmentioning

confidence: 99%

“…Although some of these events are classified as intermediate depth earthquakes, and a few are located in the outer rise of the Pacific slab, they are included in the record due to the possibility of poor event locations in the early 1900s – up to 1° laterally and 30 km in depth for the best‐located events, with earthquakes at 40–100 km depth being particularly problematic [ Gutenberg and Richter , 1954]. In addition to uncertainty in earthquake locations and depths, magnitude estimates for these events have been calculated and revised numerous times [ Gutenberg and Richter , 1954; Gutenberg , 1956; Richter , 1958; Abe and Kanamori , 1979; Abe , 1981; Abe and Noguchi , 1983; Pacheco and Sykes , 1992]; the most recent magnitude revisions are listed in Table 1.…”

Section: Introductionmentioning

confidence: 99%

“…The seismic record used by Pacheco et al [1993] to compute seismic coupling coefficients along this margin included only two large events: 1902 Ms 7.4 occurring near 18°N, 146°E and 1934 Ms 7.1 occurring near 22.5°N, 144°E (Figure 2 and Table 1, events 5 and 10). No shallow thrust earthquakes larger than Ms 7.4 have been recorded and clearly located in the central and northern parts of the Mariana Islands during 1897 to 2010 [ Gutenberg and Richter , 1954; Abe and Kanamori , 1979; Abe , 1981; Pacheco and Sykes , 1992]. Given the relationship for seismic coupling and fault parameters used by Pacheco et al [1993], the absence of earthquakes larger than Ms 7.4 over the last ∼110 years requires that a giant earthquake the size of the great Chilean or Alaskan earthquakes (Mw > 9) occur in order to seismically release the accumulated strain (Table 2, first row).…”

Section: Introductionmentioning

confidence: 99%

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Seismogenic characteristics of the Northern Mariana shallow thrust zone from local array data

Emry

Wiens

Shiobara

et al. 2011

Geochem. Geophys. Geosyst.

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The Northern Mariana seismogenic zone has no shallow thrust earthquakes larger than Ms 7.4 in the historical seismological record and is traditionally considered ‘decoupled’ or ‘aseismic’. During the 2003–2004 Mariana Subduction Factory Imaging Experiment, we recorded local shallow earthquakes throughout the central and northern regions of the Mariana forearc using an array of terrestrial broadband and ocean bottom seismographs. Accurate locations for both the 2003–2004 local seismicity as well as earthquakes with Global Centroid Moment Tensor (GCMT) solutions from 1976 to 2008 were obtained using the hypocentroidal decomposition relocation method and a local velocity model. Additionally, focal mechanisms for the largest 2003–2004 earthquakes were determined using regional waveform inversion. Thrust faulting earthquakes occur along the Mariana megathrust between depths of 20–60 km, showing that the lack of great shallow thrust earthquakes does not result from a narrow seismogenic zone and that most seismicity occurs where the downgoing plate contacts the overriding mantle wedge. Clusters of small plate interface earthquakes with Ml 1.6–4.7 occur within patches 100–120 km west of the trench at depths of 30–45 km. Furthermore, the larger GCMT earthquakes (Mw 4.9–5.8) occur mostly updip and downdip of the patches of smaller earthquakes recorded by our local array and is suggestive of changes in the fault properties with depth. Clusters of small, forearc earthquakes occur discontinuously along the length of the Mariana subduction zone, showing that Northern Mariana is variable both along the strike of the margin and with depth along the seismogenic zone. We propose that the lack of great (Mw > 8) thrust faulting earthquakes is due in part to the variable frictional heterogeneity along the megathrust.

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“…Seismic energy release, on average, has a pronounced peak within the transition zone (410 to 660 km depth) [Abe and Kanamori, 1979]. Transition zone seismicity shows strong geographic variability (Fig.…”

Section: Introductionmentioning

confidence: 99%

Tonga slab deformation: The influence of a lower mantle upwelling on a slab in a young subduction zone

Gurnis¹,

Ritsema²,

Heijst³

et al. 2000

Geophysical Research Letters

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Abstract. There are fundamental geographic variations in the deformation of slabs in the transition zone. The seismic energy release and morphology of the Tonga slab show that it is deforming faster and has accumulated more deformation than any other slab. We show that Tonga overlies the edge of the large-scale Pacific superplume. There is no substantial aseismic penetration into the lower mantle beneath Tonga, consistent with initiation of subduction during the Eocene. Other major subduction systems overlay seismically fast structures. For long-lived subduction systems, the lower mantle tends to pull down on slabs while in Tonga the lower mantle pushes upward, partially accounting for the intense deformation. The perturbation to the state of slab stress due to large-scale mantle flow is 10 to 40 MPanearly as large as that expected from slab pull.

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Temporal variation of the activity of intermediate and deep focus earthquakes

Cited by 76 publications

References 21 publications

The 1909 Taipei earthquake-implication for seismic hazard in Taipei

The 1909 Taipei earthquake-implication for seismic hazard in Taipei

Seismogenic characteristics of the Northern Mariana shallow thrust zone from local array data

Tonga slab deformation: The influence of a lower mantle upwelling on a slab in a young subduction zone

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